How To Install Windows without USB Drive (No 3rd Party Software Required)

It is possible to perform a clean Windows installation without using a USB drive or third‑party software. This method relies entirely on built‑in Windows features, making it both secure and straightforward.

Download the ISO

• Visit Microsoft’s official site and download the Windows ISO (Windows 10 or 11).

Create an Installer Partition

• Open Disk Management (Windows Key + X → Disk Management).
• Shrink your main drive (C:) by about 10 GB (10240 MB). In some cases, shrink 9 GB (9216 MB) and extend later during setup.
• Create a new simple volume using the unallocated space.
• Name it Windows Installer and format it as NTFS.

Copy ISO Files

• Right‑click the ISO and select Mount.
• Copy all files from the mounted ISO (virtual DVD drive).
• Paste them into the new Windows Installer partition.
• This partition now acts as a bootable installer.

Boot into Recovery

• Restart your PC into Advanced Startup (Recovery Mode).
• Hold Shift and click Restart.
• Navigate to Troubleshoot → Advanced Options → Command Prompt.

Confirm Drive Letters

• In Command Prompt, type:

  diskpart  
  list volume

• Identify the drive letter of the installer partition (e.g., D:).
• Exit DiskPart.

Launch Setup

• Type:

  D:\setup.exe

  or

  D:  
  setup.exe

• Replace D with the actual installer partition letter.
• This starts the Windows installer directly from the partition.

Perform Clean Install

• Choose Install Windows.
• Delete old system partitions (do not delete the installer partition).
• Select the remaining unallocated space for installation.
• Windows will install, reboot several times, and guide you through the Out‑of‑Box Experience (OOBE).

After Installation

• You’ll boot into a fresh Windows desktop.
• You can keep the installer partition for future reinstalls or delete it later via Disk Management.
• If deleted, adjust partitions as needed (recreate recovery partition, extend C:, etc.).

This method provides a clean Windows installation without external tools, relying only on built‑in features. It’s efficient, secure, and ideal for users who prefer a streamlined setup process.